Hi I bought my 2006 Jazz on the 5th Jan, the windows keep getting steamed up. the garage I bought  the car from claimed it was just damp due to cleaning of the inside of the car before I bought it??

Yesterday I noticed water round the spare wheel. The Question is how is the water getting in and how to stop it any ideas?

Hi Buddy,   welcome to Jazz ownership .  This problem is common on Mk1's i'm afraid !  The sealant around the rear hatchback welded and seamed joints develop cracks over time and allow water to get into the boot.

You can , as I did keep removing the interior trim , and trying to track where its coming from using newspaper or wallpaper lining paper , cut into strips , to try to get a 'trace' . I even renewed the rear hatchback rubbers, (at great expense).  All to no avail .!  So after 9 years of ownership and 150000 miles , I found that under the rear floor there is a bracing band that goes from one side to the other. This has a hole in the middle , So fed up with sponging out the spare wheel well , I drilled two 10mm holes in the boot floor level with the middle of the bracing band . 

Hey presto , yes , water comes form above but not below , and runs out . 

This was my fix , and I'm not saying you should do the same, but on car worth less than a grand , it will stop the damp smell and water surging up and into the rear floors, if the water is allowed to accumilate. 

Water collecting under spare wheel & causing rust in well, & probably  rust on Jack:

Simplest solution is to drill one or two 6mm holes at lowest point in its floor [underneath the boot lock] whilst ensuring not hit any cables on underside [none on my 2003 Jazz].  Any rain-water will drain, and any surplus will evaporate safely.